The present invention is directed to holders for a sensor. The holders apply pressure to the sensor to prevent a venous blood signal without dampening the arterial blood signal and are optically opaque to shield ambient light from reaching the sensor.
1. A sensor holder for holding a reflectance type oximetry sensor against a patient's skin, the sensor holder comprising:
a base portion having an adhesive bottom surface adapted to temporarily stick the base portion onto the patient's skin, the base portion having a central void therein that is bordered by at least one inner wall; and
a roof portion positioned above the central void and attached to the base portion so as to form an interior cavity between the roof portion and the at least one inner wall, wherein the interior cavity is dimensioned to accept the oximetry sensor,
wherein the roof portion and the base portion are configured so that when the sensor holder is positioned over the oximetry sensor and stuck on a patient's skin, the oximetry sensor exerts an upward force against the roof portion, and an interaction between the roof portion and the base portion causes the roof portion to exert a downward force on the oximetry sensor,
wherein the roof portion and the base portion are configured so that the upward force against the roof portion is directed radially outward, with respect to the central void, from the at least one inner wall,
wherein the roof portion and the base portion are connected radially beyond a region that is adjacent to the at least one inner sidewall and extends radially outward from the at least one inner sidewall, and
wherein the roof portion and the base portion are not connected within the region.
2. The sensor holder of claim 1 , wherein the downward force exerted on the oximetry sensor is high enough to block venous blood flow in a region of skin beneath oximetry, the sensor, but not high enough to block arterial blood flow in the region.
3. The sensor holder of claim 1 , wherein the roof portion is optically opaque, and wherein the apparatus further comprises a shroud for blocking light that is positioned about an entrance to the interior cavity.
4. The sensor holder of claim 1 , wherein the base portion and the roof portion are made of substantially flat flexible material, the region is horseshoe shaped, and the base portion and the roof portion are connected using a permanent adhesive that is applied radially beyond the horseshoe shaped region, but is not applied within the horseshoe shaped region.
5. The sensor holder of claim 4 , wherein the sensor holder has at least one radial slit running inwards from an outer edge of the sensor holder.
6. The sensor holder of claim 4 , further comprising at least two flanges that extend radially outward from the base portion, the flanges having a lower surface with an adhesive disposed thereon, and wherein the roof portion is optically opaque.
7. The sensor holder of claim 1 , wherein the base portion and the roof portion are made of substantially flat flexible material and the region is horseshoe shaped, and wherein the sensor holder further comprises a substantially flat horseshoe shaped intervening member that is affixed to either the lower surface of the roof portion or an upper surface of the base portion in the horseshoe shaped region.
8. The sensor holder of claim 7 , wherein the sensor holder has at least one radial slit running inwards from an outer edge of the sensor holder.
9. The sensor holder of claim 7 , further comprising at least two flanges that extend radially outward from the base portion, the flanges having a lower surface with an adhesive disposed thereon, and wherein the roof portion is optically opaque.
10. The sensor holder of claim 9 , further comprising a protrusion configured to extend down from the roof portion into the interior cavity, and wherein the roof portion is black, closed cell polyethylene foam having a thickness of about 1/16th of an inch, the base portion is black, closed cell polyethylene foam having a thickness of about 1/32nd of an inch, and the protrusion has a thickness of about ⅛th inch.